I short circuited the 3V3, 5V0 and the 12V rail in turn. The power supply did shut down, and once the short was removed and the unit switched off for at least one second, resumed normal operation. Although listed here at the beginning of the testing section, I tend to leave this test until the very end, in case it doesn't quite go to plan.

The DC output voltage load regulation of the Thermaltake Toughpower XT 775W is excellent with little or no drop on the main 3V3, 5V0 and 12V rails from zero to full load, which is illustrated by the straight lines on the graphs. The -12V rail is a little on the low side and shows the characteristic rise towards -12V as the power supply is loaded but it at all times remains well inside the limits set down by the ATX12V V2.2 specification.